Eccentric power yoke



July 2, 1940. H. J. BAUMGARDNER 2,206,525.

ECCENTRIC POWER YOKE Filed June 9, 1938 lll" HARRY J. BAUMGARDNER Patented July 2, 1940 UNITED STATES PATENT OFFICE ECCEN'IRICr POWER YOKE Harry .I, Baumgardner, Kiefer, Okla.

Application June 9, 1938, Serial No. 212,829

3 Claims.

This invention relates to the art of well drilling and particularly to eccentric power units employed as a source of power common to a plurality of well pump jacks or the like. Such units are of well known construction, generally ernbodying a driven eccentric operatively connected with a plurality of pump jack operating rods or members arranged radially with respect to the eccentric 1 and pivotallyconnetced thereto at spaced points by means vof yokes. 'As the eccentric moves through an vorbit when driven, the -plurality of jack operating members are individually reciprocated Vto accomplish their function.

When a well is disconnected the separation is effected at a point remote from the power eccentric, and this leaves a considerable length of its pump jack operating member swinging loosely with respect to the eccentric. The loose connection, relieved of its load, entails rapid wear on the yoke and to a far greater extent than when the yoke is tensioned by the load of the pump jack. Such wear necessitates frequent replacement of yokes and is a source of delay as well as of expense.

The present invention has 'as an object the provision of a yoke having self-contained means maintaining an adequate tension on its connection with an eccentric, suicient to take up lost motion at all times irrespective of whether or `not the particular pump jack operating member associated with the yoke is connected to its jack.

Another object is to provide an eccentric power yoke having resilient means automatically operable to absorb shock and prevent undue wear on the shackle pin or bolt by which the yoke is pivotally connected to a power eccentric.

A further object is to provide a yoke of the character above indicated, and which is adaptable to interchangeable connection with various types of pump jack operating members.

Other objects will be readily apparent to those skilledin the art.' While the-instant disclosure constitutes an exposition of the best means I have thus far devised for reducing the invention to practice, it is to be understood that the structural details may be modified and varied as desired within the limits imposed by the scope of the invention as claimed.

In the drawing, wherein like characters of reference designate like parts throughout the several views:

Figure l is a top plan View, partly broken away, of a power eccentric unit as operatively connected with a plurality of pump jack operating members by means of yokes constructed in accordance with the invention.

Figure 2 is a side elevation of one of the yoke connections, withv an element of the eccentric shown partly in section. ,5

Figure 3 is a section taken on the line 3--3 of Figure 1.

Figure 4 is a section taken on the line I-d of Figure 3.

Figure 5 is a transverse section taken on the 1 0 line 5-5 of Figure 3.

. Figure 6 is a transverse section line 6--6 of Figure 3.

Figure 7 is a fragmentary elevation, partly in section, illustrating a yoke as connected with .23.1.4.5 a jack operating member of a form different from that shown in the preceding views.

A power eccentric of a well known typeis shown in Figure 1 and comprises a frame 8 supporting a shaft 9 driven by a pulley Ill operable I.20 in the usual manner by a belt drive, notfshown, to rotate the shaft. Fixed on the shaft 9 is a pinion II meshed with a ring gear I 2 which is` xedly connected to an eccentric I3 which, as the gear I2 rotates, moves in an orbital path. The 25 eccentric is of circular form and carries the peripherally mounted eccentric strap I4 which is in the form of an annulus, thevrnounting being of such nature that the strap IB is capableoi circumferential shifting movement on and rela- 5,30 tive to the eccentric I3. l

The strap I4, as shown in Figure 1, is provided with a peripheral series of radially projecting lugs I5 having rounded outer faces integral with the strap and substantially equidistantly spaced -z35 apart therearound. Each lug is `bored 'as at it to receive therethrough the shank of a shackle pin or bolt I1.

The structural elements and assembly thus far taken on the described are of conventional design and forma@ no part of the invention except as they into the general combination.

In service, the power eccentric unit is positioned at a suitable point and a desired number of well pump jack operating members I8 leading 45 from different wells are operatively connected to' the unit by means of kyokes I9 pivo-tally secured to the eccentric strap lugs I5 through the agency of the shackle elements II. During rotation of the gear I2 the orbital movement of the ec- 50 centric I3 shifting Within the strap I4 effects a reciprocation of the individual operating members I8 leading to the diierent wells, transmitting the requisite operating power.

Each yoke I9 comprises a pair of complemental 55 enter sections 2D of counterpart formation, rectangular in cross section to provide a plane outer face 2| and a plane inner face 22 parallel thereto. Each section is formed at one end with an integral semi-cylindrically reduced portion 23 provided with a semi-cylindrical axial bore 24, and at its other end with a reduced, tapered and externally threaded attaching nipple 25 which is also provided with a semi-cylindrical bore 26 extending inwardly longitudinally of the plane inner face 22 of the section into communication with an enlarged transverse semi-cylindrical socket 21.

The pump jack operating members I3 of Fig- 'I ures l, 2 and 3 constitute rods provided at their ends with laterally enlarged rounded heads 23 which, when the yoke sections are assembled with their plane inner faces engaging one another as shown in Figure 3, are received in the registering sockets 2'! with the rod shanks housed in the bores 26. The width of the sockets 2 is preferably greater than the thickness of the rod head 28 in order to provide for a slight relative longitudinal movement between rod end' and yoke when the parts are connected.

The yoke connection is'eiiected by a pair of parallel metal straps 29 apertured at one end for pivotal engagement over the shackle element il in the adjacent lug of' the A eccentric strap ld; the opposite end of each strap being inwardly offset to bear flatly upon the outer plane face 2! of the adjacent section 2D and being secured thereto by a pair of reversely positioned bolts 30 having nuts 3| thread-ed over their ends and overlying the strap offsets, with the bolt Shanks passed through the respective strap offsets and yoke sections substantially inalignment with and at opposite sides'of the sockets 2. It will be obvious that as the nuts are tightened up the parts will be securely clamped together and that the assembled yoke will pivot as a unit on its associated shackle element Il.

When the yoke sections 2i) are engaged their registering reduced portions 23 provide a cylinder which receives a cylindrical plunger 32 closed at its outer end and provided with a cylindrical bore extending inwardly from its opposite end and housing a coiled expansion spring'33 which'bears at onevend against the closed outer end of the plunger, and at its' other end against the body of v the engaged sections.

The spring projected plunger 32 slides freely in its housing cylinder and the tension of the spring 33 is such that the closed outer end of the plunger will at all times be forcibly engaged against the rounded outer face of the associated eccentric strap lug l5, so that, while the yoke can swing on its pivot at the shackle il, the spring provides a means imposing a constant force yieldingly urging the yoke radially outwardly of the power eccentric strap to absorb shock and take up lost motion and loose play in the connection. Furthermore, the tension of the spring ris such that the plunger has a braking action on the rounded face of the eccentric strap lug of sufficient magnitude to prevent loose pivoting of the yoke thereon.

The yoke is adapted for use either with pump jack operating members such as the rods I8 or with operating members made up of connected pipe lengths, as shown in Figure 7. When employed with pipe or threaded tubing constituting the operating member i8', as shown in Figure 7, the yoke is secured to the member by means of a connecting collar 36 threaded at one end to the member I8 and at its other end to the nipple formed by the registering nipple portions 25 of the sections 20.

Having thus described the invention, what is claimed is:

1. A power eccentric connecting yoke comprising a pair 'of parallel metal straps adapted for pivotal connection at one end With a power eccentric element, a pair of complemental sections 4disposed in abutting engagement between the other ends of said straps and adapted for connection with an operating member, securing elements clamping said sections against each other and said, straps against the sections, each of said sectionsA having a semi-cylindrical portion extending between said straps and said portions cooperating to provide a cylinder, and a spring projected plunger slidable axially in said cylinder.

2. A yoke for connecting a power eccentric and an operating member, comprising a body formed of a pair of complemental sections of counterpart formation and having plane inner faces'in abutting engagement, each section being provided with a semi-cylindricalibore extending-axiallyinwardly from each end and opening to its plane inner face, said bores at one end of the sections -being adapted to embrace an operating member,

means for clamping said sections tcgetherin assembled relation, a yokey arm rigidly secured to each section, said arms extending in parallel spaced relation beyond the other end of the sections, a plunger slidable between said sections in the registering bores at the end beyond which said arms extend, and an expansion spring housed in said registering bores behind thevplunger.

3. A power eccentric connection for a pump jack operating rod, comprising a pair of parallel -rnetal straps providing yoke arms adapted at one end for pivotal connection with a power eccentric element, apair of. complemental blocks having opposed plane contacting faces disposed between said arms at the other end and spacing the same, cooperating sockets in the contacting faces of said blocks for attaching engagement thereoffand a coiled expansion spring housed between said extensions in rear of said plunger.

HARRY.' J. BAUMGARDNER. 

